Fixing bucket alignment for group by

[jnutzmann]

This addresses issue #2005

It makes sure the buckets land on natural boundaries. If the minimum time specified falls in the middle of a bucket, it returns bucket, but only data after the minimum time.

[otoolep]

Thanks @jnutzmann -- the test suite failed however. Can you dig into that? You can find the test output on the "Details" link above, and you can also run the tests manually too, of course.

[jnutzmann]

Yup. Already have a fix that I am working on. Seems like there are two issues. First in how it calculates the number of points to return and also in the expected result (should return a bucket with null). I'll update my branch shortly.

[otoolep]

Great.

You must also sign the CLA, if you have not already done so.

@pauldix

[jnutzmann]

I signed the CLA this morning.

As far as the change to the test goes, I believe the previous expected result was incorrect, but I want to make sure you agree. The previous result placed the the point occurring at "2000-01-01T00:00:10Z" in the "2000-01-01T00:00:00Z" bucket when grouped by 10s. This should rather be in the "2000-01-01T00:00:10Z" bucket. We get null for the "2000-01-01T00:00:00Z" bucket, since the previous point occurs at "2000-01-01T00:00:00Z" and we limit to "2000-01-01T00:00:05Z" in the query.

Seem correct?

[toddboom]

@jnutzmann I'm check on this now. Your logic makes sense - I'll verify and let you know.

[otoolep]

Unit test changes look good to me -- thanks @jnutzmann. +1 on this change.